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Protractors

School

Although protractors began to appear in practical geometry textbooks in the 18th century, it was not until the turn of the 20th century that they were used systematically in mathematics teaching in American schools. Some protractors were small and inexpensive, intended for purchase and use by individual students. These might be made from new materials, such as plastic. Other protractors for educational use were oversized, designed for teachers to provide demonstrations of concepts at the blackboard. Two protractors in the collection were manufactured in Japan and displayed at the 1876 World's Fair to help demonstrate the modernization of education in that nation.

This paper semicircular protractor is divided by degrees and marked by tens from 10 to 170 degrees in both directions. The letter A is printed in the bottom left corner of the protractor, and B is printed in the bottom right corner of the protractor. Centered under the origin point of the protractor is printed the inventor's mark: Combination Protractor, Rule, and Square (/) W. W. Hart, University of Wisconsin.

A ruler along the top edge is divided to 1/8-inch and marked by ones from 0 to 5. A ruler along the bottom edge is divided to millimeter and marked by ones from 0 to 12. The typeface of the inventor's mark is similar to that shown in Hart's textbooks published in the 1920s, such as Walter Wilson Hart, Junior High School Mathematics, vol. 1 (Boston: D. C. Heath & Co., 1921), vii, 131. See also MA*304722.06.

In the early 20th century, some authors of mathematics textbooks and their publishers began to include protractors in the endpapers of the books. They wanted middle and high school students to informally experience geometry through drawing and experiment before moving on to constructing formal geometrical proofs. Walter W. Hart, a professor of mathematics at the University of Wisconsin, went so far as to design a combination protractor and ruler for insertion in the textbooks he authored with professional mathematics textbook author Webster Wells.

By 1921, Hart's protractor was described and illustrated in the text with a cardboard version included for student use. If students lost their protractors, teachers could order replacements from D. C. Heath & Co. for four to five cents each, depending on the quantity ordered. By 1926, Hart was boasting that his invention had anticipated the standards recommended in 1923 by the Mathematical Association of America's National Committee on Mathematical Requirements. This example probably dates from one of Hart's later textbooks.

This paper semicircular protractor is divided by degrees and marked by tens from 10 to 170 degrees in both directions. The letter A is printed in the bottom left corner of the protractor, and B is printed in the bottom right corner of the protractor. Centered under the origin point of the protractor is printed the inventor's mark: COMBINATION PROTRACTOR, RULE, AND SQUARE (/) W. W. HART, UNIVERSITY OF WISCONSIN. A ruler along the top edge is divided to 1/8-inch, and marked by ones from 0 to 5. A ruler along the bottom edge is divided to millimeters and marked by ones from 0 to 12. This protractor was donated by the Brown University mathematics department in 1973. It is notably discolored and stained. See also MA*304722.07.